There is an available technology where radio transmission apparatuses in which a radio signal transmission function is added to a switch are arranged at various locations of a production line or the like and, based on radio signals from the respective radio transmission apparatuses, a single apparatus (hereinafter, described as a state display apparatus) displays states of the various locations. Moreover, a radio transmission apparatus in which a radio signal transmission function is added to a switch is also referred to as a radio switch or the like.
When constructing a system (hereinafter, described as a state display system) by combining a plurality of the radio transmission apparatuses with the state display apparatus described above, a position of each apparatus is determined so that communication between each radio transmission apparatus and the state display apparatus can be carried out in a favorable manner. However, there may be cases where, after the state display system is constructed, the addition of some kind of equipment to the production line or the like prevents communication between some of the radio transmission apparatuses and the state display apparatus from being favorably performed. In addition, there may be cases where a failure of some of the radio transmission apparatuses and/or the state display apparatus prevents communication between some of the radio transmission apparatuses and the state display apparatus from being favorably performed.
Therefore, a technique is desired which enables a user to comprehend that communication between a radio transmission apparatus and a state display apparatus can no longer be carried out in a favorable manner.